Synthesis, Growth, Spectral, Optical and Mechanical Properties of an Organic Single Crystal: (E)-2-(4-Chlorostyryl)-1-Methylpyridin-1-Ium Iodide Hydrate

International audienceAn organic stilbazolium derivative of (E)-2-(4-chlorostyryl)-1-methylpyridin-1-ium iodide hydrate (CMPI) crystal was grown from the methanol-acetonitrile mixed solvent by slow evaporation technique at room temperature. The crystal system and cell parameters of the grown crystal are verified by single crystal X-ray diffraction analysis. The functional groups of CMPI were identified from FTIR spectrum. The optical behaviour of the grown crystal was analysed by UV-vis-NIR studies. The mechanical stability of the grown crystal was investigated by Vicker's microhardness tester. The third-order nonlinear optical property of the grown crystal was elucidated by employing the single beam Z-scan technique. Introduction. The nonlinear optical (NLO) properties of organic molecular materials have been the object of intense research due to potential applications in various photonic technologies. Organic molecules with significant NLO behaviour originate from a strong donor-acceptor intermolecular interaction with high chromophore density and delocalised π-electron system [1]. Normally organic chromophores exhibit high and fast nonlinearities than their inorganic counterparts. The stable packing of chromophores in organic crystals, which in turn results in high thermal, mechanical and photochemical stability [2]. Stilbazolium derivatives are found to be the interesting groups of organic materials because their molecular nonlinearity can be easily preserved by varying the counter-ions to achieve the desired physical and chemical properties [3]. Among them, the organic stilbazole crystal, 4-N,N-dimethylamino-4'-N'-methylstilbazolium tosylate (DAST) is of wide interest owing to its outstanding NLO properties and electro-optical properties [4]. The variation of counter-ions in stilbazolium salt is a simple and highly successful method to create new materials with macroscopic optical nonlinearities [5]. These points motivated us to design and synthesis stilbazolium crystals having a π-conjugated system with the good nonlinear response. Though the information about the X-ray crystallographic structural data of (E)-2-(4-chlorostyryl)-1-methylpyridin-1-ium iodide hydrate (CMPI) is available, there is no report on the growth of this material for NLO applications. Hence, we report in this present investigation synthesis, growth, spectral, optical, mechanical, and third-order nonlinear optical properties of the organic stilbazolium derivative, CMPI